As a solid image pickup element (hereinafter, simply referred to as “image pickup element”) used in a digital camera, the development of a CMOS image sensor using a CMOS (Complementary Metal Oxide Semiconductor) is ongoing.
The image pickup element as a semiconductor device provided with the CMOS image sensor includes a plurality of pixels formed in the upper surface of a semiconductor substrate. The plurality of pixels are arranged in a matrix shape when seen in a plan view for detecting light. In addition, a photoelectric conversion element such as a photo diode to generate electric charges is formed in each of the plurality of pixels.
Japanese Patent No. 2600250 (Patent Document 1) discloses a technique in which a plurality of light collecting units are arranged on a plurality of light receiving units in a solid-state image pickup device. Japanese Patent No. 3478796 (Patent Document 2) discloses a technique in which photoelectric conversion areas are two-dimensionally arranged in a solid-state image pickup device. Japanese Patent No. 3551437 (Patent Document 3) discloses a technique in which a plurality of light receiving units, a plurality of color filters, and a plurality of light collecting units are provided on a substrate in a solid-state image pickup device. Japanese Patent No. 4419658 (Patent Document 4) discloses a technique in which a plurality of light receiving units and a plurality of on-chip lenses are provided in a solid-state image pickup device. Japanese Patent No. 4004302 (Patent Document 5) discloses a technique in which a plurality of pixels configured of a light receiving element, a color filter, and a micro lens are disposed in a matrix shape in an image pickup element. Japanese Patent Application Publication Laid-Open No. 2007-88851 (Patent Document 6) discloses a technique in which an image pickup element including a light receiving element and a micro lens, and an image pickup lens are provided in an image pickup device.